Japanese Beetles in Toronto

Photo used under Creative Commons license
Copyright Benny Mazur

Japanese Beetles have made their way through the Toronto landscape at an unprecedented rate this year. Now, I’m no “bugspert” so who knows if it’s the heat or just the unusually dry summer we've had that has made their population explode this year, but I do have a few tips to get them out of your garden.

What are they?

Japanese beetles are about 1.5 centimetres long with a copper coloured body and green head. They originate from, surprise, Japan.

Having no natural predators in North America these pesky little buggers have been eating and breeding their way through the foliage unchecked.

New adults tend to emerge around the end of June when they immediately start feasting on and defoliating your garden. They tend to congregate in packs and by mid-July they are already laying eggs in your soil.

How to get rid of them?

Step 1, squish them. Step2, squish them again.

Ok, ok, effective, but a little gross. So try drowning them. Seriously. Get a bucket of water with some added dish detergent. Sweep any you see off you plants and into your soapy water.

You can also try using a small hand held vacuum or dust buster. Just vacuum the critters off plants and empty them into soapy water.

If you’re dealing with a bigger invasion you might want to try commercially available Japanese beetle traps specifically for this purpose. I tried some traps this past week and a client was able to collect three bags worth of beetles. The Safers brand beetle trap seems to perform the best.

The beetle traps work using pheromones and pollen scents. So you will want to keep the traps as far away from the vegetation you are trying to protect as possible. They should be set preferably at a distance of about 50 feet and downwind if at all possible.

Of course now we are approaching fall and the Japanese beetle larvae are already crawling around in the soil, possibly munching on the roots of your grass. You’ll want to kill as many as possible now before they are able to winter in your soil and pop out next spring.

The most natural way to handle this is to get some beneficial nematodes for your fine local garden centres and nurseries. Nematodes, specifically the Heterorhabditis spp., or Hb variety, can help control larval production. You’ll need to mix the nematodes with water at home and apply to your grounds when the air temperature is above 15 degrees Celsius. You’ll want to get this done within the first few weeks of September and remember to apply well to all soils, lawn, flowerbeds and even plant containers.

Well, I hope this helps and stay dialed in for more articles on fall maintenance and prepping your space for spring.

Keep up the bug fight,

Jennifer Hayman